Numerous medical diagnostic and therapeutic procedures require access to the internal organs of a living organism. Some of these procedures can be performed without traditional surgical incisions by utilizing catheter-based apparatus to enter blood vessels. Usually, catheter-based apparatus require a needle to be inserted through the skin and directed into a blood vessel. This provides a conduit for extending a metal or polymer guide wire through the needle and into the vasculature. After positioning the guide wire in the conduit, the needle can be removed and replaced with a hollow tube or catheter directed over the guide wire into the blood vessel. The tube or catheter provides access for administration of certain substances and/or for passage of additional equipment that will be used to perform manipulations within the vasculature or within other organ systems accessible through the vasculature.
To prevent bleeding upon completion of a catheter-based intravascular procedure, the catheter must be removed and the puncture site sealed. In the low-pressure environment of the venous system, a small needle puncture is readily sealed by the brief application of pressure to the site and application of a light dressing, such as a bandage. This method is widely utilized after needle stick procedures such as blood drawings.
However, when punctures are created with larger caliber apparatus (such as catheters) in the high-pressure environment of arteries, the puncture created will not readily seal with the application of brief pressure. Prolonged external pressure may be required for fifteen to thirty minutes and may lead to substantial discomfort at the puncture site for the patient and/or a significant failure rate with late bleeding and hematoma formation.
In the past, several methods have been proposed to address this problem. For instance, one prior apparatus utilizes a marker to indicate the position of the bandage with respect to the wound to be treated in order to position externally applied pressure at or near a puncture site. Another apparatus uses a pad which, when moistened by fluid from a wound, expands and exerts pressure against a wound.
Another apparatus utilizes laser energy directed through a balloon tipped catheter into the vascular tract and positioned just outside the outer wall of the blood vessel. The balloon is used to create a covering for the vascular puncture. The laser is used to create a laser “weld” or seal in the adjacent tissue.
Another apparatus uses both a balloon tipped catheter and an absorbable plug. The plug is used to occlude the vascular access tract and provide hemostasis. The balloon tipped catheter serves as a positioning anchor for antegrade insertion of the vascular plug and must be removed from the patient after plug deployment.
Yet another apparatus uses a balloon tipped catheter arranged so as to pass into the vascular lumen by means of the extant access sheath. After this procedure it is withdrawn to the intraluminal side of the blood vessel puncture to provide temporary hemostasis. A pro-coagulant slurry is then injected into the vascular access tract to promote coagulation. During this time, the balloon tipped catheter remains inflated. After a suitable period of time necessary to promote blood coagulation, the balloon tipped catheter is deflated and withdrawn from the access tract.
Each of these approaches has its own unique set of shortcomings. The prior apparatus lack both a means for precise positioning of a pressure-generating component against a puncture tract and a structure designed to optimize the pressure that is to be applied to such a site. Therefore, there is a need in the art for an apparatus that hemostatically closes a vascular puncture site without leaving a hematoma within the puncture tract, while minimizing patient discomfort. Ideally, such an apparatus would quickly, painlessly and reliably achieve hemostasis upon withdrawal of vascular catheters, and consequently reduce patient discomfort, staff time and the unfavorable failure rate associated with vascular hemostasis and the risk of hematoma formation.